Furnace conveyor



June 28, 1960 s. F. WILBUR FURNACE CONVEYOR 2 Sheets-Sheet 2 Filed April 16, 1959 1 1 .ugrgll u JNVENTOR. SINCLAIR FRANCIS WILBUR mwm A TTORNE Y United States Patent '0 FURNACE CONVEYOR Sinclair F. Wilbur, 22 Stone Tower Lane, Barriugton, RJ.

Filed Apr. 16, 1959, Ser. No. 806,856

6 Claims. (Cl. 214-18) This invention relates to a furnace conveyor and more particularly to a conveyor for furnaces having a plurality of chambers; each chamber being atmospherically isolated from the adjacent chamber.

An object of the present invention is to provide a conveyor for a furnace having a plurality of atmospherically isolated chambers.

. Another object of the present invention is to provide an individual positive moving conveyor in each chamber of a multiple chamber furnace with means to transfer a work carrying tray over the threshold separating the chambers.

Another object of the present invention is to provide a conveyor with means for passing a tray in a continuous and uniform movement through a plurality of separate furnace chambers. The chambers forming part of an atmospherically controlled furnace of the high heat variety (100 degrees-2250 degrees Fahrenheit). The moving parts of the conveyor are always in compression and never under tension engagement with the tray.

And another object of the present invention is to provide a conveyor with means to actuate doors between separate furnace chambers and thereby maintain a high degree of purity of atmosphere in the individual chambers. Thus, minimizing atmospheric contamination of the atmosphere of one chamber with the atmosphere of an adjacent chamber.

Still another object of the present invention is to provide continuous conveyor means in a furnace having a plurality of chambers. The conveyor means providing for intermittent operation within individual chambers.

And still another object of the present invention is to provide a screw thread conveyor in conjunction with a work carrying tray in which the screw thread is under a constant uniform load as it pushes the work carrying tray through a furnace having an extremely high temperature.

And still another object of the present invention is to provide a screw thread type conveyor which moves a work tray through a furnace with means on the work tray to override the screw thread and be advanced through the furnace ahead of the screw conveyor cycle.

Other objects of the present invention will become apparent in part and be pointed out in part in the following specification and claims.

In the past conveyors of the continuous type in atmosph'ere controlled high heat furnaces consisted of a continuous belt. The belt subjected alternately to heat baths of 1700 degrees Fahrenheit and room temperatures stretched and contracted repeatedly, creating fatigue which shortened the life span of the belt. Frequent break downs with material isolated within the furnace was the rule. In addition the belt was always under tension as it pulled the work load through the hot furnace. This tension further decreased the life of the belt.

The present invention obviates all of the disadvantages of prior art conveyors in high heat furnaces by pushing Ice the work load, instead of pulling the work load, through the furnace and by isolating sections of the conveyor in the individual furnace chambers. Thus eliminating alternate heat baths and the consequent heat caused stresses.

The present conveyor has obviated shock and jerks in conveyor operation by providing a uniformly rotating screw thread. Thus obviating breakdowns occasioned by the jerking of the conveyor belt in taking up slack. The present conveyor is located in the area of lowest temperature within a heat chamber.

Similar characters of reference refer to similar parts in the following drawings, in which:

Figure 1 is a side elevational view of a multiple chamber, high heat, atmospherically controlled furnace provided with the new and improved furnace conveyor.

Figure 2 is a fragmentary transverse cross sectional view taken along line 2--2 of Figure 1.

Figure 3 is a fiagmentary horizontal cross sectional view taken along line 3--3 of Figure 1 showing trough construction.

Figure 4 is a fragmentary vertical cross sectional view taken along line 4--4 of Figure 3.

Figure 5 is a fragmentary horizontal cross sectional view taken along line 5--5 of Figure 1.

Figure 6 is a fragmentary vertical cross sectional view taken along line 66 of Figure 5 with the tray slightly advanced across the threshold.

Figure 7 is a fragmentary cross sectional view slightly enlarged, taken along line 77 of Figure 6 looking in the direction of the arrows.

Figure 8 is a fragmentary sectional view taken along line 8-8 of Figure 6.

Figure 9 is a fragmentary sectional view taken along line 9-9 of Figure 7.

Figure 10 is a diagrammatic view illustrating the mechanism for opening and closing the door between chambers.

Attention is directed to Figure 1 wherein is illustrated a four chamber atmosphere controlled furnace provided with the new and improved furnace conveyor. Chamber 11 is a pre-heat chamber having doors 12 and 13 which atmospherically seal pre-heat chamber 11.

Chamber 14 is a high heat chamber having doors 13 and 15 which atmospherically isolate high heat chamber 14. Chamber 16 is a cooling chamber having doors 15 and 17 which atmospherically isolate cooling chamber 16. Chamber 18 is a discharge chamber having doors 17 and 19 which atmospherically isolate discharge chamber 18.

Chamber 11 is supported upon legs 21, 22 and 23. Chamber 14 is supported upon legs 24, 25, 26 and 27.

Legs 28, 29, 30 and 31 support chambers 16 and 18.

A motor mount 32 is provided to support an electric motor 33 and a gear reduction unit 34. A shaft 35.

operatively connected to motor 33 through gear reduction unit 34 is rotatively supported in bearings housed in brackets 36, 37, '38, 39, 4G, 41, 42 secured to legs 21, 22, 24, 27, 29, 30 and 31 respectively. A bearing bracket 43 secured to a stanchion 44 functions as an outboard mounting for shaft 35. Magnetic clutches 45, 46, 47 and 48 having sprocket wheels 50, 51, 52 and 53 respectively, forming part of the idling sections of said magnetic clutches, are secured to shaft 35.

Hearth plate supports 71 of refractory material are placed in spaced relation within the walls 70 of chamber 11. Hearth plate refractory bricks 72 are laid upon the hearth plate supports 71. A muffle 76 in the form of a hollow circular pipe is supported upon bricks 72. The construction of chamber 14 is identical to that for chamber 11. A mufile section 76D square in cross section connects chamber 11 with chamber 14. Chambers 7 16 and 18 are equivalent in construction to muflle section 76D. That is square 3 in cross section- Muflie 'section 76E connects the muffie in chamber 14 to chamber 16. Mufiie section 76? forms part of chamber 18;

A plurality of saddles 730i cast alloy are secured to muflie-76 in spaced relation. A trough comprising a 7 multiple number oi sections 74, 74A in spaced relation which ride in mulfiie 76" and upon. saddles 73. (Due end of troughsection 74 is provided with a tongue 77.7 The ninety degree turned downoppositesides- 82, 83 which ride upon the tracks 69 and guidedin the track by edges 80, 81. Tray 75 is provided with two bearings 84, 85. A- shaft 86 is rotatively mounted in bearings 84 85. A flipper 87 is provided with a bearing 88 which is rotatively mounted upon shaft 86. Two stops. 90, 91 secured to bearings- 84,85 respectively, limit the forward pivotal movement of flipper 87.. A series of weights. 92 are fixed to flipper 87 to cause it to tend to hang vertically. Tray 75 is provided with a plurality oi flippers 87 illustrated; as threein number inFigure S. Tray 75 is provided with a slot;79;for purposes which will presently appear. a

rotate the section of screw 100 located within Opposite'endsof hollow circular pipe mufl le 76- are provided with water cooled pillow blocl r bearings 9 3, 93A. In'dividual screws 100 are located in the semi circular housingsof troughs 74, 74A, and are-rotatively mounted in pillow'block bearings" 93,-93A. Similarly;

screw 101 is mounted in pillow'bloclrs 94, 94A. 'There are similar individual screwsin'chambers .16 and 18 'Ihe ends Of'the shafts of screws 100,? 101 etc., a1'c 1 7 provided with sprockets 104, 105; 106,-10 7 respectively,

and are aligned with sprockets 50, 51,52, 53, respectively Sprocket'chains connect the respective pair of sprockets to each other. i a a K Each square section of mulfie76D, 76E, etc.,' is-provided with a platform or. threshold 110 (see Figure. 6),.

which is ina horizontal plane with the top'edge of screw 7 100, vfor purposes which will presently appear.

11'; square section's 76D, 76E and 76F and in. chamber 18;"a dog similar to dog'lll is pivotally mounted to be aetuated'by-"tray 75. Dog: 111 operativelycontrols a p 7 momentary contact switch 11 2which energizes; a" sole- 'noid valve"llacausing anair valve piston114 to move. upwardly and thereby blockconduit 115 and lopenconi dint 116. ,fPiston 1'17 isithereby} caused to shift rand j open door 118- for example. 'Dog 120- is actuated by fthefupward movement of; door 118. Actuationof' dog 120 closes momentary contact switch;1 21,,.ther1eby;ener- .gizingisolenoid va1ve123 and causingair valve piston-114 tomovedownward, thereby blocking conduit 116. andopening conduit 115 to shift piston 117 and'clos'e door 118. In a like manner doors 15, 17 and"19- are actu-- r a high heat chamberil t. Thecontrolpaneljalso con V troisamagneti'cgclutches 45,46, 47,48 and electric rnotor 100m chamber 11;

pre-heat chamber 11. By energizing and de-energizing magnetic clutch 45, screw 100 is caused to rotate or not rotate through sprockets 50, 104 andrtheir chain drive connection, so that the work load on tray will remain in pre-heat chamber 11 for a period of time under control of the electrical control-panel. 7

After the pre-determined pre-heat period has expired, magnetic clutchw45 will be: energized" and thereby rotate screw which will push tray 75 carrying'a work load through p're-heat chamber 11. The convolutions' of screw 100 pushing tray'75 throughflipper 87 are under compression and are located in the bottom of chamber 11. Continued movement of tray 75' through chamber 11 will cause the edge of tray 75 to rotate dog 111 and thereby close momentary contact switch 112 which energizes solenoid valve 113 to shift air valve piston 114 and thereby open; door 118 to allow tray 75 to pass across threshold between pre heat chamber 11. and high heat chamber 14 and en'terchamber' 14 to engageflipper 87 with the convolutions of'screw 101 in. charm ber 14.

Astray 75 approaches threshold 1-10 itleaves' theigu id ance provided by edges 80, 81 of. trough" 74. The sides through chamber 11'. In additionthreshold 110' (see- Figures 5 and 6.) as a raised portion causes the first of the plurality of flippers 87 to swing or pivot rearwardly and thereby disengage theconvolutions' of screw 100.

The distance-fromthe forward. flipper S7A to the'rean most flipper 8713 must be'greater than. the length of thresholdjl lti so that. the forwardfflipper 87Afengage's the convolutions of screw 101'incha mber14 before the flipper 87B is disengaged frorri theconvolution's of screw It will .be observed that asthe for:- ward flipper 87A on tray: 75 pivots out of contact with the convolutionsof screw 100 the other'of the plurality offlippers 87, 87B still engaging screw 100 and will continue to push tray 75 .across threshold 110 until flipper 87A'eiiga'ges screw "101 in chamber'1'4; Screw 101 then takes over to continue to push tray 75' through chamber 14. the remaining chambers. a

If for any reasonit is necessary or desirable'to withdrawthe tray 75 from the chambers, all that. is riecesis toopen the doors, reach into'the chambers witha hookedwithdrawin'girod, engage slot 79'with the hook and pull the tray'towa rd the normal 'exit chamber. Flippers 87, 87A. and 87B will bounce across the top of In like manner tray 75 passes through the convolutions of the several screws: and across thei thresholds.

33. The control panel also controlsethe electricicircuit V which opens entering do onllf The-glow bars and electrical-;control panel are not shown because they-are in cidental to the -present1inventi'on and well known in the art. 1 V

' I In operation entering, door-12is opened. A tray 75" carrying a work load is pushed through the :door open- V .ing'until. a flipper- 87 falls; between the-'convolutions of.

screw 100; Deer-12h closed. QMotor 33 is energized 7 to rotate shaft 35. 7 Magnetic; clutch. 45; is;energized-;to

other examples given withoutdeparting.

.Screws 100,. 101 etc. be]tabricated completeiy from refractory. material. Prior conveyorswere' unable to be completely fabricated from this highheat rWistantmaterial. V 1 5 'Having shown and described a preferred embodiment of the present invention, by way of example, it should be realiied that structural changes could bemade and spirit or scope of this invention.

What Lclaimis: 7V V 1'. A a furnace conveyor. for usein? a chamber having: a

rnufile; consisting of'a trough" having-a horizontal-plat form'constituting. a track, with opposite parallel'edgesof said-platform.bentvertically to form guiding .edge sf forsaid track, the center of said-platformlformedinto a cir- 1 cular housing, a screw thread rotatively mounted on oppositeends in said rnufile and located in said 'circular housingwith' the" top edge of said screw extending .ver- 'tically above'thehorizontal plane ofsaid horizontal plat- 7 form, a' tray formed with'opposite lyertical parallel edges which slideonsaid track and-lie betwcengthe edgesof said track,. a flipper 'pivotally mountedto asaid tray, a stop fixed to: said tray to limit: the pivotal niove V oineith'er' the ment of said flipper in one direction, said flipper engaging said screw to push said flipper against said stop to move said tray along the track on said trough.

2. A furnace conveyor for use in an atmosphere controlled furnace having a plurality of chambers, a separate conveyor in each chamber, a tray for holding the Work, a plurality of pivotal means on said tray adapted to engage said conveyors for moving said tray through said chambers, movable closure means for separating said chambers one from the other, mechanism for moving said movable closure means to open position and means adjacent said doors and engaged by said tray for actuating said mechanism to allow said tray to pass from one chamber to the next adjacent chamber.

3. A conveyor for use in an atmosphere controlled furnace comprising a plurality of chambers, a door between adjacent chambers to isolate one chamber from the next adjacent chamber, a plurality of screws, one for each chamber, means to rotate each screw independent of the screw in the adjacent chamber, a track fixed in each chamber, a tray, pivotal means on said tray to engage the screw in each chamber to slide said tray along said track, said last named pivotal means disengaging the screw in one chamber and engaging the screw in the adjacent chamber to slide said tray from the track in one chamber to the track in the adjacent chamber and means operable in timed relation of the sliding of the tray through a chamber to open and close the door between adjacent chambers to allow said tray to pass from one chamber to the adjacent chamber.

4. A conveyor for use in an atmosphere controlled furnace comprising a multiple number of separate chambers, a multiple number of separate hollow circular mnflies, one fixed in each of said separate chambers, a multiple number of hollow square muffles, one for each side of each chamber, each hollow square muflie fixed to the end of a hollow circular muffle with the hollow square muffle between adjacent chambers uniting said adjacent chambers to form a continuous hollow path through the multiple number of hollow square and circular muflies, a multiple number of doors slidably mounted, one in each hollow square muffle, a plurality of screws, one for each separate chamber, means to rotatively mount each screw in each chamber independently of the screw in the adjacent chamber, a track in each hollow circular mufiie, said square muffles being of a width to form a continuation of the track in the adjacent mufile, a tray, two flippers mounted to each tray to pivot through an arc of approximately ninety degrees, said flippers engaging the screw to push said tray along the track, the hollow square muflies having means to disengage said flippers from the screw, and said two flippers spaced from each other a distance greater than the width separating one screw from the next adjacent screw so that one flipper is always in engagement with one screw to push said tray along the continuous track.

5. A conveyor for use in an atmosphere controlled furnace comprising a plurality of chambers, a threshold between adjacent chambers, a door slidably mounted in each threshold, a trough fixed in each chamber, a plurality of screws, rotatively mounted, one in each trough, means to rotate said screws, a track on each trough in horizontal alignment with the threshold of the adjacent chamber, a tray having two or more screw engaging means spaced a distance greater than the width of the threshold slidingly mounted on said track, said threshold disengaging said screw engaging means to permit said screw engaging means to pass over said threshold to engage the screw in the next trough, and means operable by said tray to open and close said doors in timed relation of the tray sliding along said track and across the thresholds.

6. A furnace conveyor for use in an atmosphere controlled furnace comprising a plurality of chambers, a plurality of muflies, one for each chamber, a plurality of muffie sections, each muflie section square in cross section and provided with a raised threshold, each mufiie section connected on opposite ends to the muflie ends of muifies in adjacent chambers, a plurality of doors one for each muffle section, each door slidingly mounted in a muffle section, mechanism for moving each door to open and closed position, a plurality of troughs one for each muflle, each trough having track means and provided with a centrally located circular housing and mounted for heat expansion and contraction in a muflie, each track means and each threshold lying in a horizontal plane, a plurality of individual screws, one for each muffle and rotatively mounted in each muflle and located in the circular housing of the trough in each muflie, a tray slidingly guided in said track means in said troughs and by the side walls of said muflie sections provided with a plurality of pivotal means for engagement with said screws, said screws pushing said pivotal means and thereby said tray along said track means and across said thresholds, said pivotal means being spaced apart a distance greater than the width of said thresholds, a drive shaft provided with a plurality of magnetic clutches, one for each screw, and drive means connecting said magnetic clutches to each of said screws whereby rotation of said drive shaft selectively rotates said screws through said magnetic clutches and means actuated by said tray to actuate saidmechanism for moving said doors from closed to open position and back to closed position.

References Cited in the file of this patent UNITED STATES PATENTS 691,723 Martin Ian. 21, 1902 1,298,285 Bogaty Mar. 25, 1919 2,726,077 Dow Dec. 6, 1955 

